Mug holder



FIG. 1 is a perspective view of the mug holder showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a rear elevational view thereof.

The ornamental design for a mug holder, as shown and described.